The present disclosure relates to development devices and image forming apparatuses including a development device.
In such image forming apparatuses, a latent image is formed on a surface of an image bearing member including a photosensitive member etc., and the latent image is developed into a visible toner image by the development device. The development is performed, for example, by the two-component development technique, which uses a two-component developer. The development device which is employed in the two-component development technique includes a developer container, a development roller, and a mixing/transporting member. The developer container stores a two-component developer containing magnetic carrier particles and toner particles. The development roller supplies the developer to the image bearing member. The mixing/transporting member transports the developer in the developer container while mixing the developer, to supply the developer to the development roller.
In the development device employed in the two-component development technique, the toner is consumed during development. On the other hand, the carrier particles are circulated in the development device without being consumed. Therefore, the carrier particles deteriorate over time in the development device. As a result, the toner charging performance of the carrier particles gradually becomes lower.
Therefore, some techniques of reducing or preventing the deterioration in the charging performance of the carrier particles have been proposed. For example, in order to reduce or prevent the deterioration in the charging performance, a development device is configured so that a new supply of the carrier-containing developer is added to the developer container, and some excess developer is discharged from the developer container. In such a development device, a developer outlet is formed on the developer container. The developer outlet is an opening through which the developer is discharged.
Incidentally, when the development device is initially driven, damage to the development device is likely to occur due to friction between its members, such as the development roller etc. In order to reduce or prevent the occurrence of the damage, the development device is previously loaded with the developer. The amount of the developer previously loaded is set to such a value that a layer of toner can be formed on the development roller.
Therefore, when the development device with the developer outlet is transported with it being mounted in the body of an image forming apparatus or with it being packed separately from the body of an image forming apparatus, the developer loaded in the development device is likely to leak through the developer outlet and scatter due to vibration, shock, etc. during transportation. The scattering developer contaminates the inside of the image forming apparatus, for example.